SPINNING UNIT, SPINNING MACHINE, AND YARN PROCESSING METHOD
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a spinning unit and a spinning
machine.
2. Description of the Related Art
A spinning unit described in Japanese Unexamined Patent
Application Publication No. 2011-38225 is conventionally known. In
such a spinning unit, a yarn accumulating roller for temporarily
accumulating a spun yarn is provided downstream of a spinning device.
In order to wind the spun yarn on an outer peripheral surface of the
yarn accumulating roller, the spinning unit is provided with a yarn
hooking member which is integrally rotated with the yarn accumulating
roller. Since the yarn hooking member is integrally rotated with the
yarn accumulation roller while being engaged with the spun yarn, the
spun yarn is wound around the outer peripheral surface of the yarn
accumulating roller. The spinning unit includes a yarn removing member.
While the spun yarn is engaged with the yarn hooking member, the yarn
removing member moves a yarn path of the spun yarn to remove the spun
yarn from the yarn hooking member.
SUMMARY OF THE INVENTION
When the yarn removing member removes a spun yarn from the yarn
hooking member, the yarn removing member may fail to remove the spun
yarn from the yarn hooking member. Conventionally, detection is not
carried out to confirm whether the spun yarn has been removed from the
yarn hooking member when the yarn removing member is operated.
An object of the present invention is to provide a spinning unit
and a spinning machine capable of detecting whether or not a spun yarn
is removed from a yarn hooking member.
A spinning unit comprises a spinning device adapted to produce
a spun yarn by twisting a fiber bundle, a yarn accumulating roller
provided downstream of the spinning device in a yarn travelling
direction and adapted to accumulate the spun yarn by rotating and winding
the spun yarn around an outer peripheral surface thereof, a yarn hooking
member arranged downstream of the yarn accumulating roller and adapted
to wind the spun yarn around the outer peripheral surface of the yarn
accumulating roller by rotating with the yarn accumulating roller while
being in contact with the spun yarn, a yarn removing member adapted
to remove the spun yarn from the yarn hooking member, and a yarn removal
detecting section adapted to detect a removal of the spun yarn from
the yarn hooking member.
A spinning machine comprises a plurality of spinning units, and
a service cart arranged capable of moving among the plurality of the
spinning units and provided with the yarn removal detecting section,
wherein the yarn removal detecting section detects the spun yarn moved
in the peripheral direction of the yarn accumulating roller by the yarn
hooking member rotating while making contact with the spun yarn, and
to detect the removal of the spun yarn from the yarn hooking member
in accordance with a detection result of the spun yarn moving in the
peripheral direction of the yarn accumulating roller.
A yarn processing method during a yarn joining operation in a
spinning machine with a spinning device, a yarn joining device and a
yarn accumulating device, wherein directly after a yarn cut or breakage,
a low quality yarn is produced due to slip of the yarn in the yarn
accumulating device, wherein the yarn joining operation is not started
immediately after an upper yarn from the spinning device has been guided
to the yarn joining device, but it is waited until a sufficient amount
of yarn is again collected in the yarn accumulating device to avoid
slip therein, then the first yarn of low quality is removed from the
yarn accumulating device and replaced by normal yarn produced after
a sufficient amount of yarn had again been collected in the yarn
accumulating device, and only then the yarn joining operation is started
in the yarn joining device, thus avoiding to include the low quality
yarn in the produced yarn.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a front view illustrating a spinning machine according
to one embodiment of the present invention.
Fig. 2 is a longitudinal sectional view of the spinning machine
illustrated in Fig. 1.
Fig. 3 is a block diagram of a main structure of the spinning
machine illustrated in Fig. 1.
Fig. 4 is a longitudinal sectional view of a yarn accumulating
device illustrated in Fig. 1.
Fig. 5 is an external perspective view of the yarn accumulating
device illustrated in Fig. 1.
Fig. 6 is a front view schematically illustrating a structure of
a yarn accumulating roller and its periphery illustrated in Fig. 1.
Fig. 7 is a side view schematically illustrating a structure of
the yarn accumulating roller and its periphery illustrated in Fig. 1.
Fig. 8 is a flowchart describing a first half of control of
unwinding a portion with unstable yarn quality from the yarn
accumulating roller.
Fig. 9 is a flowchart describing a last half of the control of
unwinding a portion with unstable yarn quality from the yarn
accumulating roller.
Fig. 10 is a timing chart of unwinding a portion with unstable
yarn quality from the yarn accumulating roller.
Fig. 11 is a longitudinal sectional view illustrating how a
suction pipe and a suction mouth (illustrated in Fig. 1) catch an upper
yarn and a lower yarn.
Fig. 12 is a longitudinal sectional view illustrating how a
portion with unstable yarn quality is unwound from the yarn accumulating
roller.
Fig. 13 is a side view schematically illustrating the yarn
accumulating roller and its periphery when a yarn removing lever
(illustrated in Fig. 7) is located at a lifted position.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Next, a spinning unit and a spinning machine according to an
embodiment of the present invention will be described with reference
to the drawings. Herein, "upstream" and "downstream" respectively
refer to upstream and downstream in a traveling direction of a spun
yarn during a spinning operation.
The spinning machine 1 includes a plurality of spinning units 2
arranged in line. The spinning machine 1 includes a yarn joining cart
3, a blower box 80, and a motor box 5. In a plant provided with the
spinning machine 1, an operator passage extending in a direction in
which the spinning units 2 are arranged is provided at a side of a yarn
path with respect to the yarn joining cart (service cart) 3. An operator
can operate each spinning unit 2 or monitor its operational status at
the operator passage.
Each spinning unit 2 includes a draft device 7, an air-jet spinning
device 9, a yarn accumulating device 12, a waxing device (wax applying
device) 30, and a winding device 13 in this order from upstream to
downstream. The draft device 7 is provided in the vicinity of an upper
end portion of a frame 6 of the spinning machine 1. A fiber bundle 8
fed from the draft device 7 is spun with the air-jet spinning device
9. After the spun yarn 10 spun with the air-jet spinning device 9 passes
through a yarn clearer 52, the spun yarn 10 is conveyed further
downstream with the yarn accumulating device 12, and waxed with the
waxing device 30 . Then, the spun yarn 10 is wound with the winding device
13, and a package 45 is formed.
The draft device 7 drafts a sliver 15 into the fiber bundle 8.
As illustrated in Fig. 2, the draft device 7 includes the following
four pairs of rollers: a pair of back rollers 16, a pair of third rollers
17, a pair of middle rollers 19 provided with an apron belt 18, and
a pair of front rollers 20. A bottom roller of each of the pairs of
rollers 16, 17, 19 and 20 is driven to rotate by power from the motor
box 5 or an individually provided driving source (not illustrated).
Each pair of rollers 16, 17, 19 and 20 is driven to rotate at a different
rotation speed, and as a result, the sliver 15 fed from the upstream
is drafted into the fiber bundle 8 and conveyed to the air-jet spinning
device 9 located downstream. As illustrated in Fig. 3, among the pairs
of rollers 16, 17, 19 and 20 provided in the draft device 7, a pair
of rollers that is driven to rotate by the power from an individually
provided driving source (not illustrated) (in the embodiment of the
present invention, the pairs of rollers 16 and 17) is controlled by
a unit controller 60. However, if a driving source (not illustrated)
provided in the motor box 5 drives all of the pairs of rollers 16, 17,
19 and 20 to rotate, a control unit for controlling driving of the driving
source provided in the motor box 5 may control the rotation of the pairs
of rollers 16, 17, 19 and 20.
The air-jet spinning device 9 twists the fiber bundle 8 using
whirling airflow to produce the spun yarn 10. Although a detailed
description or an illustration will be omitted, the air-jet spinning
device 9 includes a fiber guiding section, a whirling airflow generating
nozzle, and a hollow guide shaft body. The fiber guiding section guides
the fiber bundle 8 fed from the draft device 7 to a spinning chamber
formed in the air-jet spinning device 9. The whirling airflow
generating nozzle is provided around a path of the fiber bundle 8 and
generates whirling airflow in the spinning chamber. Fiber ends of the
fiber bundle 8 in the spinning chamber are reversed and whirled with
the whirling airflow. The hollow guide shaft guides the spun yarn 10
from the spinning chamber to outside of the air-jet spinning device
9. As illustrated in Fig. 3, the whirling airflow is generated or
stopped by the control of the unit controller 60.
The yarn accumulating device 12 is provided downstream of the
air-jet spinning device 9. The yarn accumulating device 12 includes
the following functions: drawing the spun yarn 10 from the air-jet
spinning device 9 by applying a predetermined tension thereto,
preventing slackening of the spun yarn 10 by accumulating the spun yarn
10 fed from the air-jet spinning device 9 during a yarn joining operation
performed by the yarn joining cart 3, and adjusting a tension such that
tension change at the winding device 13 is prevented from propagating
to the air-jet spinning device 9. As illustrated in Fig. 2, the yarn
accumulating device 12 includes a yarn accumulating roller 21, a yarn
hooking member 22, an upstream guide 23, an electric motor 25, a
downstream guide 26, an accumulated amount detecting sensor 27, and
a yarn removing lever (yarn removing member) 28.
The yarn hooking member 22 is capable of engaging with (hooking)
the spun yarn 10. By being integrally rotated with the yarn accumulating
roller 21 while being engaged with the spun yarn 10, the yarn hooking
member 22 can guide the spun yarn 10 to an outer peripheral surface
21a of the yarn accumulating roller 21.
The yarn accumulating roller 21 can wind and accumulate the spun
yarn 10 on the outer peripheral surface 21a thereof. The yarn
accumulating roller 21 is driven to rotate at a constant rotation speed
by the electric motor 25 controlled by the unit controller 60. When
the yarn accumulating roller 21 is rotated, the spun yarn 10 guided
to the outer peripheral surface 21a of the yarn accumulating roller
21 by the yarn hooking member 22 is wound as if to tighten the yarn
accumulating roller 21, and hence the spun yarn 10 located upstream
of the yarn accumulating device 12 is drawn. Accordingly, the spun yarn
10 can be continuously drawn from the air-jet spinning device 9.
When the spun yarn 10 accumulated on the yarn accumulating roller
21 reaches or exceeds a certain amount, a contact area between the yarn
accumulating roller 21 and the spun yarn 10 becomes large, and hence
a slip or the like will hardly occur. Therefore, when the yarn
accumulating roller 21 is rotationally driven under a state in which
the spun yarn 10 of the certain amount or more is wound on the yarn
accumulating roller 21, the yarn accumulating device 12 can draw the
spun yarn 10 from the air-jet spinning device 9 at a stable speed without
causing a slip or the like. In the following description, the certain
amount (that is, a yarn accumulated amount in which no slip occurs and
the force to draw the spun yarn 10 is stabilized) may be referred to
as a minimal accumulation amount.
The accumulated amount detecting sensor 27 detects in a
non-contact manner, the amount of the spun yarn 10 accumulated on the
yarn accumulating roller 21, and transmits a detected amount to the
unit controller 60.
The upstream guide 23 is arranged slightly upstream of the yarn
accumulating roller 21. The upstream guide 23 functions as a guiding
member to properly guide the spun yarn 10 to the outer peripheral surface
21a of the yarn accumulating roller 21. The upstream guide 23 also
functions as a twist stopper for preventing propagation of twists of
the spun yarn 10 from the air-jet spinning device 9 to the downstream
of the upstream guide 23.
The downstream guide 2 6 is arranged slightly downstream of the
yarn accumulating roller 21. The downstream guide 26 regulates a path
of the spun yarn 10 swung by the rotating yarn hooking member 22 in
a peripheral direction of the yarn accumulating roller 21. The
downstream guide 26 stabilizes a travelling path of the spun yarn 10
located downstream of the downstream guide 26, and guides the spun yarn
10.
The yarn removing lever 28 is arranged upstream of the downstream
guide 2 6 in the vicinity of a downstream end portion of the yarn
accumulating roller 21. The yarn removing lever 28 can swing around
a swing shaft 28b.
The yarn clearer 52 is arranged between the air-jet spinning
device 9 and the yarn accumulating device 12. The yarn clearer 52
monitors a thickness of a travelling spun yarn 10. When detecting a
yarn defect in the spun yarn 10, the yarn clearer 52 transmits a yarn
defect detection signal to the unit controller 60. The unit controller
60 that has received the yarn defect detection signal stops the air-jet
spinning device 9 from twisting the fiber bundle 8 using the whirling
airflow to cut the spun yarn 10.
As illustrated in Figs. 1 and 2, the yarn joining cart 3 includes
a splicer (yarn joining device) 43, a suction pipe 44, a suction mouth
46, a pushing arm 47, a pneumatic cylinder (moving section) 49, and
a yarn movement detecting sensor (yarn removal detecting section) 50.
When a yarn breakage or a yarn cut occurs in a spinning unit 2, the
yarn joining cart 3 runs on a rail 41 fixed to the frame 6 and stops
at the relevant spinning unit 2 to perform a joining operation (splicing
operation) . The yarn joining operation refers to a series of operations
in which yarn ends formed due to a yarn breakage or a yarn cut are caught
and joined. The series of these operations may be referred to as a yarn
joining cycle.
The suction pipe 44 can vertically swing around an axis. The
suction pipe 44 can suck and catch a yarn end (upper yarn) of the spun
yarn 10 fed from the air-jet spinning device 9, and guide the yarn end
to the splicer 43. The suction mouth 4 6 can vertically swing around
an axis. The suction mouth 46 can suck and catch a yarn end (lower end)
of the package 45 supported by the winding device 13, and guide the
yarn end to the splicer 43. The operation of sucking the yarn ends by
the suction pipe 44 and the suction mouth 4 6 is controlled by the unit
controller 60. Although a detailed description will be omitted, the
splicer 43 untwists both yarn ends and then twists the yarn ends together
using the whirling airflow to join the upper yarn and the lower yarn.
The pushing arm 47 is arranged at a tip end portion of the pneumatic
cylinder 49 as an actuator. By driving the pneumatic cylinder 4 9, the
pushing arm 47 is moved to an upper advanced position to lift the yarn
removing lever 28, and thus the yarn removing lever 28 can be moved
to the lifted position. The driving of the pneumatic cylinder 49 is
controlled by the unit controller 60.
The yarn movement detecting sensor 50 detects the spun yarn 10
moved in the peripheral direction of the yarn accumulating roller 21
by the yarn hooking member 22 being rotated while being engaged with
the spun yarn 10 (the spun yarn 10 moved as if to travel around the vicinity
of the downstream end portion of the yarn accumulating roller 21 by
the yarn hooking member 22 being rotated) . The detection result by the
yarn movement detecting sensor 50 is transmitted to the unit controller
60.
The waxing device 30 is provided between the yarn accumulating
device 12 and the winding device 13. A travelling detecting sensor (yarn
removal detecting sensor) 31 is provided in the waxing device 30. The
travelling detecting sensor 31 detects at least one of travelling of
the spun yarn 10 to be waxed with the waxing device 30 along a yarn
path and stop of travelling. The detection result by the travelling
detecting sensor 31 is transmitted to the unit controller 60.
The winding device 13 includes a cradle arm 71 that is supported
to be capable of swinging around a supporting shaft 70. The cradle arm
71 can rotatably support the bobbin 48 used to wind the spun yarn 10.
The winding device 13 includes a winding drum 72 and a traverse
device 75. The winding drum 72 can be driven while making contact with
an outer peripheral surface of the bobbin 48 or an outer peripheral
surface of the package 45. The traverse device 75 includes a traverse
guide 76 that can be engaged with the spun yarn 10. By driving the
winding drum 72 by an electric motor (not illustrated) while
reciprocating the traverse guide 7 6 by a driving means (not illustrated) ,
the package 45 making contact with the winding drum 72 is rotated and
the spun yarn 10 is wound while being traversed.
The blower box 80 is provided with an air supplying source
(negative pressure source) (not illustrated) that generates air to be
supplied to each section of the spinning unit 2, the yarn joining cart
3 and the like.
Next, a specific structure of the yarn accumulating device 12 will
be described with reference to Figs. 4 and 5.
The yarn accumulating roller 21 is a roller member made from an
abrasion-resistant material, and is fixed to a motor shaft 25a of the
electric motor 25. On the outer peripheral surface 21a of the yarn
accumulating roller 21, provided that a side on which the yarn hooking
member 22 is provided is a tip end, and a side on which the electric
motor 25 is provided is a base end, a base end side tapered portion
21b, a cylindrical portion 21c and a tip end side tapered portion 21d
are provided in this order from the base end to the tip end.
The cylindrical portion 21c is formed to slightly taper toward
the tip end side and also to be smoothly connected with the tapered
portions 21b and 2Id at both sides without difference in level. The
size of the cylindrical portion 21c is appropriately determined so that
at least a minimal amount or more of the spun yarn 10 can be accumulated.
The accumulated amount detecting sensor 27 includes a minimum
accumulated amount detecting sensor 27a and an excessive accumulation
detecting sensor (yarn removal detecting sensor) 27b. The minimum
accumulated amount detecting sensor 27a and the excessive accumulation
detecting sensor 27b are arranged to face the cylindrical portion 21c.
Each of the base end side tapered portion 21b and the tip end side
tapered portion 2 Id is formed in a gradual tapered shape with a larger
diameter at a corresponding end side. On the outer peripheral surface
21a of the yarn accumulating roller 21, the base end side tapered portion
21b functions to smoothly move the supplied spun yarn 10 to a small
diameter portion from the large diameter portion until the spun yarn
10 reaches the cylindrical portion 21c located at the middle to orderly
wind the spun yarn 10 around the surface of the cylindrical portion
21c. The tip end side tapered portion 21d functions to prevent a
sloughing phenomenon in which the wound spun yarn 10 sloughs all at
once while the spun yarn 10 is being unwound from the yarn accumulating
roller 21. The tip end side tapered portion 21d also functions to
sequentially rewind the spun yarn 10 from the small diameter portion
to the large diameter portion at the end side so as to maintain smooth
drawing of the spun yarn 10.
As illustrated in Figs . 4 and 5, the yarn hooking member 22 arranged
at the tip end side of the yarn accumulating roller 21 is arranged
coaxially with the yarn accumulating roller 21. The yarn hooking member
22 includes a flyer axis 33 and a flyer 38 fixed to the tip end of the
flyer axis 33.
The flyer axis 33 is rotatably supported relative to the yarn
accumulating roller 21. A permanent magnet (not illustrated) is
attached to either one of the flyer axis 33 or the yarn accumulating
roller 21, and a magnetic hysteresis material (not illustrated) is
attached to another one of the flyer 33 or the yarn accumulating roller
21. These magnetic mechanisms generate resistance torque against the
rotation of the yarn hooking member 22 relative to the yarn accumulating
roller 21. With such resistance torque, the yarn hooking member 22 is
rotated in response to the rotation of the yarn accumulating roller
21, and accordingly, the yarn hooking member 22 is integrally rotated
with the yarn accumulating roller 21. When a force surpassing the
resistance torque is applied to the yarn hooking member 22, the yarn
hooking member 22 is relatively rotated with respect to the yarn
accumulating roller 21.
The flyer 38 is properly curved toward the outer peripheral
surface 21a of the yarn accumulating roller 21, and is configured to
be engaged with the spun yarn 10 (to hook the spun yarn 10). When the
flyer 38 is integrally rotated together with the yarn accumulating
roller 21 under a state in which the spun yarn 10 has not been wound
around the yarn accumulating roller 21, the flyer 38 is engaged with
the spun yarn 10. The spun yarn 10 engaged with the rotating flyer 38
is swung around by the flyer 38, and guided to and wound around the
outer peripheral surface 21a of the rotating yarn accumulating roller
21.
Next, the spun yarn 10 wound around the yarn accumulating roller
21 will be described. After passing through the upstream guide 23, the
spun yarn 10 is guided from the base end side of the yarn accumulating
roller 21 to the outer peripheral surface 21a thereof, and then wound
around the cylindrical portion 21c several times. Then, after passing
through the flyer 38, the spun yarn 10 drawn from the tip end side of
the outer peripheral surface 21a is conveyed downstream through the
downstream guide 26.
Under a state in which the spun yarn 10 has been wound around the
yarn accumulating roller 21 as illustrated in Fig. 5, when a force is
applied on the spun yarn 10 to draw the spun yarn 10 engaged with the
flyer 38 towards the downstream side, a force to rotate the yarn hooking
member 22 is applied to the flyer 38 so as to unwind the spun yarn 10
from the tip end side of the yarn accumulating roller 21. Therefore,
if a yarn tension at downstream of the yarn accumulating device 12 (a
yarn tension between the yarn accumulating device 12 and the winding
device 13) is great enough to surpass the resistance torque (that is,
if a yarn tension of a predetermined value or more is applied to the
spun yarn 10 engaged with the flyer 38), the yarn hooking member 22
is independently rotated from the yarn accumulating roller 21, and the
spun yarn 10 is gradually unwound from the tip end side of the yarn
accumulating roller 21 through the flyer 38.
When the yarn tension at the downstream of the yarn accumulating
device 12 is not strong enough to surpass the resistance torque, the
yarn hooking member 22 is integrally rotated with the yarn accumulating
roller 21. The yarn hooking member 22 functions to prevent the spun
yarn 10 from being unwound from the tip end side of the rotating yarn
accumulating roller 21.
When the tension of the spun yarn 10 at the downstream increases,
the yarn accumulating device 12 unwinds the spun yarn 10. When the
tension of the spun 10 lowers (that is, the spun yarn 10 is about to
slacken), the yarn accumulating device 12 stops the unwinding of the
spun yarn 10. Thus, the yarn accumulating device 12 can eliminate the
slackening of the spun yarn 10 and apply an appropriate tension to the
spun yarn 10. The yarn hooking member 22 operates to absorb changes
in tension applied to the spun yarn 10 located between the yarn
accumulating device 12 and the winding device 13. Accordingly, such
tension changes can be prevented from influencing the spun yarn 10
located between the air-jet spinning device 9 and the yarn accumulating
device 12. Thus, the yarn accumulating device 12 can draw the spun yarn
10 at a more stable speed from the air-jet spinning device 9.
Since the yarn accumulating roller 21 is driven to rotate at a
predetermined speed, the spun yarn 10 is wound around the base end side
of the yarn accumulating roller 21 at the predetermined speed. When
the speed at which the spun yarn 10 is unwound from the tip end side
of the yarn accumulating roller 21 is faster than the speed at which
the spun yarn 10 is wound around the base end side, the yarn accumulated
amount decreases. When the spun yarn 10 is not unwound from the tip
end side of the yarn accumulating roller 21, the yarn accumulated amount
gradually increases.
The yarn accumulating device 12 includes the yarn removing lever
28. As illustrated in Fig. 5, the yarn removing lever 28 is formed as
a substantially L-letter shaped member with a horizontally arranged
elongate portion (an operating section 28a) . A base portion of the yarn
removing lever 28 is supported by the swinging shaft 28b. The yarn
removing lever 28 is capable of swinging vertically around the swinging
shaft 28b between a lifted position and a lowered position. When the
yarn removing lever 28 is located at the lowered position, the yarn
removing lever 28 is not in contact with a yarn path of the spun yarn
10. When the yarn removing lever 28 is located at the lifted position,
the operating section 28a pushes a yarn path of the spun yarn 10 so
that the spun yarn 10 can be removed from the flyer 38. By being urged
by a spring member (not illustrated), the yarn removing lever 28 is
normally held at the lowered position. When the pneumatic cylinder 49
provided in the yarn joining cart 3 is driven, the yarn removing lever
28 is lifted by the pushing arm 47 to be moved to the lifted position.
By moving the yarn removing lever 28 to the lifted position, the
spun yarn 10 can be removed from the yarn hooking member 22. Thus, the
resistance developed when the spun yarn 10 is unwound from the tip end
side of the yarn accumulating roller 21 (i.e. resistance torque applied
to the yarn hooking member 22) will no longer influence the spun yarn
10. As a result, even if the yarn tension at the downstream of the yarn
accumulating roller 21 is weak, the spun yarn 10 can be unwound from
the yarn accumulating roller 21. By maintaining the yarn removing lever
28 lifted under the state in which the spun yarn 10 is not wound around
the yarn accumulating roller 21, the flyer 38 can be prevented from
being engaged with the spun yarn 10. As a result, the spun yarn 10 can
be controlled to be not wound around the yarn accumulating roller 21.
Next, the yarn movement detecting sensor 50 provided in the yarn
joining cart 3 will be specifically described with reference to Figs.
6 and 7. The yarn movement detecting sensor 50 is arranged at an upper
portion of the yarn joining cart 3. The yarn movement detecting sensor
50 detects in a non-contact manner the spun yarn 10 moved around the
tip end portion of the yarn accumulating roller 21 in response to the
rotation of the yarn hooking member 22 engaged with the spun yarn 10.
The yarn movement detecting sensor 50 emits a laser beam L50 from a
position located below the yarn accumulating roller 21 towards a cover
12a covering a side of the yarn accumulating roller 21. The yarn
movement detecting sensor 50 emits the laser beam L50 such that the
spun yarn 10 moving around the tip end portion of the yarn accumulating
roller 21 intersects an optical path of the laser beam L50 . Accordingly,
the spun yarn 10 moving in the peripheral direction of the yarn
accumulating roller 21 at the tip end portion of the yarn accumulating
roller 21 intermittently interrupts the laser beam L50 emitted by the
yarn movement detecting sensor 50. The yarn movement detecting sensor
50 detects the spun yarn 10 which intermittently interrupts the laser
beam L50. The detection result by the yarn movement detecting sensor
50 is transmitted to the unit controller 60.
Next, the accumulated amount detecting sensor 27 will be
specifically described with reference to Figs. 6 and 7. The excessive
accumulation detecting sensor 27b is arranged in the vicinity of the
tip end portion of the yarn accumulating roller 21. The excessive
accumulation detecting sensor 27b emits a laser beam L27b towards the
outer peripheral surface 21a of the yarn accumulating roller 21. An
emitting position of the laser beam L27b is a position where the tip
end of the spun yarn 10 is located when a predetermined length of the
spun yarn 10 has been wound around the outer peripheral surface 21a
of the yarn accumulating roller 21 from the base end side to the tip
end side. The predetermined length of the spun yarn 10 is a minimum
length to satisfy a minimal accumulation amount or more and also is
a maximum length permitted to be wound around the yarn accumulating
roller 21. The excessive accumulation detecting sensor 27b detects
whether or not the spun yarn 10 is located at the emitting position
of the laser beam L27b on the outer peripheral surface 21a of the yarn
accumulating roller 21. When the spun yarn 10 is located at the emitting
position of the laser beam L27b, an excessive amount of spun yarn 10
is wound around the yarn accumulating roller 21. That is, a
determination can be made that the spun yarn 10 is excessively
accumulated.
When the yarn hooking member 22 is rotated while being engaged
with the spun yarn 10, the spun yarn 10 moves in a space between the
outer peripheral surface 2la of the yarn accumulating roller 21 and
the excessive accumulation detecting sensor 27b. That is, in response
to the rotation of the yarn hooking member 22, the spun yarn 10 moves
in the peripheral direction of the yarn accumulating roller 21 on the
outer peripheral surface 21a thereof. The spun yarn 10 moving in the
peripheral direction of the yarn accumulating roller 21 intermittently
interrupts the laser beam L27b emitted from the excessive accumulation
detecting sensor 27b. The excessive accumulation detecting sensor 27b
also detects the spun yarn 10 that intermittently interrupts the laser
beam L27b. The detection result by the excessive accumulation
detecting sensor 27b is transmitted to the unit controller 60.
The minimum accumulated amount detecting sensor 27a is provided
at a position closer to the base end side of the yarn accumulating roller
21 than the excessive accumulation detecting sensor 27b. Like the
excessive accumulation detecting sensor 27b, the minimum accumulated
amount detecting sensor 27a emits a laser beam L27a towards the outer
peripheral surface 21a of the yarn accumulating roller 21. An emitting
position of the laser beam L27a is a position where a tip end of the
spun yarn 10 is located when the spun yarn 10 of a minimal accumulation
amount is wound around the outer peripheral surface 21a of the yarn
accumulating roller 21 from the base end side to the tip end side. The
minimum accumulated amount detecting sensor 27a detects whether or not
the spun yarn 10 is located at the emitting position of the laser beam
L27a on the outer peripheral surface 21a of the yarn accumulating roller
21. When the spun yarn 10 is located at the emitting position of the
laser beam L27a, a determination can be made that the minimal amount
or more of the spun yarn 10 has been wound around the yarn accumulating
roller 21. The detection result by the minimum accumulated amount
detecting sensor 27a is transmitted to the unit controller 60.
Next, with reference to Figs. 8 to 12, a description will be made
on a yarn processing method during a yarn joining operation in the
spinning machine 1 according to an embodiment of the present invention.
In Fig. 10, a state in which the suction pipe 44 is sucking is
indicated with "ON", and a state in which sucking of the suction pipe
44 is stopped is indicated with "OFF" . A state in which the yarn removing
lever 28 is lifted is indicated with "ON", and a state in which the
yarn removing lever 28 is lowered is indicated with "OFF".
When the yarn clearer 52 detects a yarn defect while the spun yarn
10 is being wound, the yarn clearer 52 transmits a yarn defect detection
signal to the unit controller 60. Upon receipt of such a yarn defect
detection signal ("YES" in Step S101), the unit controller 60 stops
the draft device 7 and the air-jet spinning device or the like from
spinning the fiber-bundle 8 to cut the spun yarn 10 (Step S102) . At
this time, the winding device 13 continues winding of the package 45,
and the spun yarn 10 located downstream of the cut position is once
wound into the package 45. Accordingly, the spun yarn 10 wound around
the yarn accumulating roller 21 is also wound into the package 45, and
no spun yarn 10 exists on the yarn accumulating roller 21. A portion
including the yarn defect of the spun yarn 10 is also once wound into
the package 45.
Then, the unit controller 60 transmits a control signal to the
yarn joining cart 3, and the yarn joining cart 3 travels to the relevant
spinning unit 2 in which the yarn defect has been detected (Step S103) .
Then, the yarn joining operation cycle is started. Specifically,
the unit controller 60 operates to rotationally move the suction mouth
46 to the vicinity of a surface of the package 45 (refer to Fig. 11),
and commands the winding device 13 to reversely rotate the package 45.
Accordingly, the yarn end of the lower yarn is drawn from an outer
peripheral surface of the package 45, and the yarn end is caught by
the suction mouth 46 (Step S104). Since the defective portion of the
spun yarn 10 drawn from the package 45 is sucked with suction airflow
by the suction mouth 46, a portion of the spun yarn 10 including the
yarn defect can be eliminated from the package 45.
Then, while reversely rotating the package 45, the unit controller
60 operates to swing the suction mouth 46, which is sucking the lower
yarn, to guide the lower yarn to the splicer 43. The lower yarn is guided
to the splicer 43, and also the rotation of the package 45 is stopped
(Step S105) .
At approximately the same time as the swinging movement of the
suction mouth 46, the unit controller 60 swings the suction pipe 44
to the vicinity of the downstream side of the air-jet spinning device
9 (refer to Fig. 11) . The unit controller 60 reactivates the air-jet
spinning device 9 and the like to produce the spun yarn 10 (Step S107) .
At approximately the same time as the start of the production of the
spun yarn 10, the unit controller 60 commands the suction pipe 44 to
generate suction airflow so that the suction pipe 44 can catch a yarn
end of the spun yarn 10 (upper yarn) produced by the air-jet spinning
device 9 (Step S108).
After the suction pipe 44 catches the upper yarn, the unit
controller 60 swings the suction pipe 44 downward while continuing the
suction, and the spun yarn 10 is drawn from the air-jet spinning device
9 and guided to the splicer 43 (Step S109). In the flowchart of Fig.
8, after the lower yarn is caught (Steps S104 and S105) , the upper yarn
is caught (Steps S106 and S109) . However, this flowchart indicates just
one example of the operation. The lower yarn may be caught after the
upper yarn, or the upper and lower yarns may be caught simultaneously.
After the spun yarn 10 is guided to the splicer 43, the spun yarn
10 located between the air-jet spinning device 9 and the suction pipe
44 is engaged with the flyer 38 and the winding of the spun yarn 10
on the yarn accumulating roller 21 is started. Although the winding
of the package 45 by the winding device 13 is stopped during the yarn
joining operation, the spun yarn 10 is continuously fed from the air-jet
spinning device 9. Therefore, if the spun yarn 10 is left as is, the
spun yarn 10 slackens. By winding the spun yarn 10 around the yarn
accumulating roller 21, the spun yarn 10 can be prevented from slackening.
After that, the amount of the spun yarn 10 accumulated on the yarn
accumulated roller 21 increases, and the force to draw the spun yarn
10 from the air-jet spinning device 9 increases.
Until the minimal accumulation amount or more of the spun yarn
10 is wound around the yarn accumulating roller 21, slip is likely to
occur between the spun yarn 10 and the yarn accumulating roller 21,
and the force to draw the spun yarn 10 is unstable. The spun yarn 10
drawn from the air-jet spinning device 9 until the sufficient amount
of the spun yarn 10 (minimal accumulation amount) is accumulated on
the yarn accumulating roller 21 includes many portions having a weak
yarn strength and an unstable yarn quality.
In a conventional spinning machine, when a yarn end is guided to
the splicer 43 by the suction pipe 44, the splicer 43 immediately starts
a yarn joining operation. The yarn joining operation refers to cutting,
untwisting and twisting of an upper yarn and a lower yarn located at
a predetermined position of the splicer 43, that is, a splicing operation
of the spun yarn 10. If the yarn joining operation is carried out at
the above-described timing, since a yarn with an unstable portion is
wound around the yarn accumulating roller 21, the unstable yarn portion
is also wound into the package 45.
In order to prevent the unstable yarn portion from being mixed
into the package 45, the spinning machine 1 according to an embodiment
of the present invention is configured with the following structure.
Even when the upper yarn is guided to the splicer 43 by the suction
pipe 44, the yarn splicing operation is not started immediately, and
the unit controller 60 determines whether or not the yarn accumulated
amount has reached the minimal accumulation amount by monitoring the
yarn accumulated amount on the yarn accumulating roller 21 by the minimum
accumulated amount detecting sensor 27a (Step S110). When the yarn
accumulated amount is less than the minimal accumulation amount ("NO"
in Step S110) , by maintaining the yarn removing lever 28 at the lowered
position, the spun yarn 10 is wound around the yarn accumulating roller
21 and the accumulated yarn amount increases. When the minimum
accumulated amount detecting sensor 27a detects that the accumulated
amount has reached or exceeded the minimal accumulation amount ("YES"
in Step S110), the unit controller 60 elevates the pneumatic cylinder
49 to move the yarn removing lever 28 to the lifted position (Step Sill)
to remove the spun yarn 10 from the flyer 38.
When the spun yarn 10 is removed from the flyer 38 while the yarn
accumulating roller 21 is rotating, the resistance that prevents the
spun yarn 10 from being unwound from the tip end portion of the yarn
accumulating roller 21 is eliminated. The spun yarn 10 thus can be
unwound from the yarn accumulating roller 21 even with a weak suctioning
power of the suction pipe 44 or the like. Therefore, under a state
illustrated in Fig. 12, the spun yarn 10 wound around the yarn
accumulating roller 21 is unwound and sucked by the suction pipe 44.
Accordingly, an unstable spun yarn 10 on the yarn accumulating roller
21 can be removed with the suction pipe 44.
On the base end side of the yarn accumulating roller 21, the spun
yarn 10 is newly wound by the rotation of the yarn accumulating roller
21. Since the spun yarn 10 is newly wound by the amount that has been
sucked by the suction pipe 44, the amount of the spun yarn 10 accumulated
on the yarn accumulating roller 21 can be maintained substantially
constant.
Therefore, the spun yarn 10 is drawn from the air-jet spinning
device 9 while the minimal accumulation amount or more of the spun yarn
10 is maintained. Consequently, the quality of the spun yarn 10 newly
wound around the base end side of the yarn accumulating roller 21 is
stabilized. While the spun yarn 10 with the stable quality is wound
from the base end side of the yarn accumulating roller 21, the spun
yarn 10 with unstable quality is unwound from the tip end side of the
yarn accumulating roller 21. As a result, the spun yarn 10 on the yarn
accumulating roller 21 is sequentially replaced with the spun yarn 10
with the stable quality.
A predetermined period of time required to replace all of the spun
yarn 10 accumulated on the yarn accumulating roller 21 with the spun
yarn 10 with stable quality from the start of unwinding of the unstable
spun yarn 10 by lifting the yarn removing lever 28 (that is, a period
of time necessary for disposing all the spun yarn 10 with the unstable
quality from the yarn accumulating roller 21) is previously input to
the unit controller 60. The unit controller 60 determines whether or
not the predetermined period of time has elapsed (Step S112) . After
the predetermined period of time has elapsed ("YES" in Step S112), the
unit controller 60 lowers the pneumatic cylinder 49 to lower the yarn
removing lever 28 (Step S113) . Then, the unit controller 60 starts the
yarn joining operation by the splicer 43 (Step S114).
By lowering the yarn removing lever 28, the flyer 38 is engaged
with the spun yarn 10. Accordingly, the spun yarn 10 is not unwound
from the tip end of the yarn accumulating roller 21, and slackening
of the spun yarn 10 is prevented.
During the yarn joining operation by the splicer 43, the suction
airflow continues to be generated from the suction mouth 4 6 and the
suction pipe 44 , and the spun yarn 10 is sucked. During the yarn joining
operation, the unnecessary spun yarn 10 is cut by the splicer 43, and
the unnecessary spun yarn 10 is sucked and removed.
When the yarn joining operation is finished, the unit controller
60 commands the winding device 13 to resume winding.
By removing the spun yarn 10 from the yarn hooking member 22 by
lifting the yarn removing lever 28, the spun yarn 10 with unstable
quality accumulated on the yarn accumulating roller 21 can be removed
with the suction pipe 44 and replaced with the spun yarn 10 with stable
quality. However, even if the yarn removing lever 28 is lifted, the
spun yarn 10 may not be removed from the yarn hooking member 22.
Hereinafter, Fig. 13 will be referred to describe a structure for
detecting a failure of the yarn removing lever 28 to remove the spun
yarn 10 from the yarn hooking member 28.
In accordance with the detection result of the above-described
excessive accumulation detecting sensor 27b, the travelling detecting
sensor 31 and/or the yarn movement detecting sensor 50, the unit
controller 60 can detect a failure of the yarn removing lever 28 to
remove the spun yarn 10.
First, a description will be made on a detection of a yarn removal
failure in accordance with the detection result of the excessive
accumulation detecting sensor 27b. The excessive accumulation
detecting sensor 27b can detect the spun yarn 10 moving in the peripheral
direction of the yarn accumulating roller 21 on the outer peripheral
surface 21a thereof. As illustrated in Fig. 13, when the yarn removing
lever 28 is moved to the lifted position and the spun yarn 10 is removed
from the yarn hooking member 22, the spun yarn 10 wound around the yarn
accumulating roller 21 travels towards the downstream via the yarn
removing lever 28 and the downstream guide 26. Consequently, the spun
yarn 10 does not move in- the peripheral direction of the yarn
accumulating roller 21 on the outer peripheral surface 21a thereof.
After the yarn removing lever 28 is moved to the lifted position, when
the spun yarn 10 intermittently interrupting the laser beam L27b is
no longer detected by the excessive accumulation detecting sensor 27b,
a determination can be made that the spun yarn 10 has been removed from
the yarn hooking member 22. Meanwhile, even after the yarn removing
lever 28 is moved to the lifted position, when the spun yarn 10
intermittently interrupting the laser beam L27b is detected by the
excessive accumulation detecting sensor 27b, a determination can be
made that the spun yarn 10 has not been removed from the yarn hooking
member 22.
A description will be made on the detection of a yarn removal
failure in accordance with the detection result of the travelling
detecting sensor 31. The traveling detecting sensor 31 detects whether
or not the spun yarn 10 is traveling on a yarn path in the waxing device
30. After the spun yarn 10 is cut, while the spun yarn 10 engaged with
the yarn hooking member 22 is being wound around the yarn accumulating
roller 21 in order to accumulate the minimal amount of spun yarn 10
(a state before the yarn removing lever 28 is moved to the lifted
position) , the downstream end portion of the spun yarn 10 wound around
the yarn accumulating roller 21 is sucked by the suction pipe 44.
However, since the suctioning power of the suction pipe 44 is weak,
the spun yarn 10 is not unwound from the tip end portion of the yarn
accumulating roller 21. Thus, the spun yarn 10 is not travelling at
the downstream of the yarn accumulating device 12, and the travelling
detecting sensor 31 detects that the travelling of the spun yarn 10
is stopped. When the yarn removing lever 28 is moved to the lifted
position and the spun yarn 10 is removed from the yarn hooking member
28, the resistance that prevents the spun yarn 10 from being unwound
from the tip end portion of the yarn accumulating roller 21 is eliminated.
Therefore, the spun yarn 10 can be unwound even with the weak suctioning
power of the suction pipe 44 or the like. Accordingly, the spun yarn
10 starts travelling on a yarn path at the downstream of the yarn
accumulating device 12, and the travelling detecting sensor 31 detects
the spun yarn 10 travelling on a yarn path in the waxing device 30.
When the yarn removing lever 28 is moved to the lifted position, if
a travelling of the spun yarn 10 is detected by the travelling detecting
sensor 31, a determination can be made that the spun yarn 10 has been
removed from the yarn hooking member 22 . Even if the yarn removing lever
28 is moved to the lifted position, when a travelling of the spun yarn
10 is not detected by the travelling detecting sensor 31, a determination
can be made that the removal of the spun yarn 10 from the yarn hooking
member 22 has failed.
A description will be made on the detection of a yarn removal
failure in accordance with the detection result of the yarn movement
detecting sensor 50. The yarn movement detecting sensor 50 detects the
spun yarn 10 moving in the peripheral direction of the yarn accumulating
roller 21 at the tip end portion thereof. As illustrated in Fig. 13,
when the yarn removing lever 28 is moved to the lifted position and
the spun yarn 10 is removed from the yarn hooking member 22, the spun
yarn 10 wound around the yarn accumulating roller 21 travels towards
the downstream through the yarn removing lever 28 and the downstream
guide 26. Consequently, the spun yarn 10 does not move in the peripheral
direction of the yarn accumulating roller 21 on the tip end portion
thereof. Thus, when the yarn removing lever 28 is moved to the lifted
position, if the yarn movement detecting sensor 50 does not detect the
spun yarn 10 intermittently interrupting the laser, beam L50, a
determination can be made that the spun yarn 10 has been removed from
the yarn hooking member 22. Even if the yarn removing lever 28 is moved
to the lifted position, when the yarn movement detecting sensor 50
detects the spun yarn 10 intermittently interrupting the laser beam
L50, a determination can be made that the spun yarn 10 has not been
removed from the yarn hooking member 22.
The unit controller 60 can detect a yarn removal failure of the
yarn removing lever 28 in accordance with the detection result of any
one of the excessive accumulation detecting sensor 27b, the travelling
detecting sensor 31 and the yarn movement detecting sensor 50. When
a yarn removal failure of the yarn removing lever 28 is detected, for
example, the unit controller 60 carries out control to return the yarn
removing lever 28 to the lowered position and then to move the yarn
removing lever 28 to the lifted position again to remove the spun yarn
10 from the yarn hooking member 22.
In the spinning machine 1 and the spinning unit 2 according to
an embodiment of the present invention, since a sensor for detecting
the yarn removal from the yarn hooking member 22 (the excessive
accumulation detecting sensor 27b, the travelling detecting sensor 31
and/or the yarn movement detecting sensor 50) is provided, a detection
can be carried out as to whether or not the spun yarn 10 has been removed
from the yarn hooking member 22 by the sensor for detecting the yarn
removal. Accordingly, a failure which may occur when a yarn removal
from the yarn hooking member 22 is not detected can be prevented.
The travelling detecting sensor 31 provided in the waxing device
30 and/or the excessive accumulation detecting sensor 27b for detecting
an excessive accumulated amount of the spun yarn 10 can detect whether
or not the spun yarn 10 has been removed from the yarn hooking member
22 . Accordingly, an additional sensor for detecting a yarn removal from
the yarn hooking member 22 is not necessary to be provided.
In the spinning unit 2 including an air-jet spinning device 9,
a detection can be carried out as to whether or not the spun yarn 10
hag been removed from the yarn hooking member 22.
The movement detecting sensor 50 provided in the yarn joining cart
3 detects the spun yarn 10 moving in the peripheral direction of the
yarn accumulating roller 21 at the tip end portion thereof, to detect
whether or not the spun yarn 10 has been removed from the yarn hooking
member 22.
An embodiment of the present invention has been described.
However, the present invention is not limited to the above described
embodiment, and various changes and modifications may be made without
departing from the scope of the claims
In the spinning machine 1 and the spinning unit 2 according to
an embodiment of the present invention, when a yarn defect is detected,
the air-jet spinning device 9 is stopped from generating whirling
airflow to cut the spun yarn 10. The present invention may be applied
to a spinning machine or a spinning unit that cuts a spun yarn 10 with
a cutter.
In the spinning machine 1 and the spinning unit 2 according to
an embodiment of the present invention, a yarn path is arranged such
that the spun yarn 10 travels downward in the height direction of a
machine frame from the draft device 7 arranged at the .upper portion
to the winding device 13 arranged at the lower portion. The present
invention may be applied to a spinning machine or a spinning unit in
which a yarn path is provided such that a spun yarn travels from a lower
portion to an upper portion in the height direction of the machine frame.
In the spinning machine 1 and the spinning unit 2 according to
an embodiment of the present invention, a yarn removal from the yarn
hooking member 22 is detected by the following three sensors, that is,
the excessive accumulation detecting sensor 27b, the travelling
detecting sensor 31 and the yarn movement detecting sensor 50 . However,
a yarn removal may be detected using only one of the above three sensors,
or prescribed two sensors may be used to detect a yarn removal.
In the spinning machine 1 and the spinning unit 2 according to
an embodiment of the present invention, the pushing arm 47 and the
pneumatic cylinder 4 9 are provided in the yarn joining cart 3 as a means
for driving the yarn removing lever 28. However, for example, each
spinning unit 2 may include a structure for driving the yarn removing
lever 28 . Instead of the pneumatic cylinder 49, the yarn removing lever
28 may be moved by an appropriate structure such as a rack and pinion
mechanism or a cam mechanism.
In the spinning machine 1 and the spinning unit 2 according to
an embodiment of the present invention, at least a portion of the
plurality of the bottom rollers of the draft device 7, and a traverse
mechanism of the traverse device 75 are driven together among the
spinning units 2. The present invention may be applied to a spinning
machine or a spinning unit in which each portion of a spinning unit
(e.g. the draft device, the air-jet spinning device and the yarn winding
device or the like) is individually driven in each spinning unit 2.
In the spinning machine 1 and the spinning unit 2 according to
the embodiment of the present invention, the air-jet spinning device
9 may include a needle held by a fiber guiding section and arranged
to be projected into a spinning chamber. The needle prevents twists
of the fiber bundle 8 from propagating to the upstream of the air-jet
spinning device 9. In the air-jet spinning device 9, propagation of
twists of the fiber bundle 8 may be prevented by the downstream end
portion of the fiber guiding section instead of using the needle. The
air-jet spinning device 9 may include a pair of air-jet nozzles that
applies twists in opposite directions to one another. In the spinning
machine 1 and the spinning unit 2 according to an embodiment of the
present invention, the air-jet spinning device 9 that carries out a
spinning operation with whirling airflow is provided. However, a
spinning device that carries out the spinning operation with another
method may be provided.
In the spinning machine 1 and the spinning unit 2 according to
an embodiment of the present invention, a yarn movement detecting sensor
50 is arranged in the yarn joining cart 3 that carries out a yarn joining
operation. Alternatively, the yarn movement detecting sensor 50 may
be arranged in a doffing cart that removes a fully wound package 45
from the winding device 13 and moves the package 45 to a predetermined
position. The yarn movement detecting sensor 50 may be arranged in a
service cart other than the yarn joining cart or the doffing cart. The
yarn joining cart 3 with the yarn movement detecting sensor 50 and the
doffing cart with the yarn movement detecting sensor 50 may be provided
as one cart in one spinning machine 1.
The yarn clearer 52 according to an embodiment of the present
invention detects a yarn defect in the spun yarn 10 by monitoring a
thickness of the spun yarn 10 . The yarn clearer 52 may monitor a presence
or an absence of a foreign object in a spun yarn 10, and may detect
the presence of the yarn defect when a foreign object is contained.
In Fig. 1, the spinning machine 1 includes one yarn joining cart
3. However, the spinning machine 1 may include a plurality of yarn
joining carts 3 according to the number of spinning units 2 provided
therein. Likewise, a plurality of doffing carts may be provided.
A spinning unit includes a spinning device, a yarn accumulating
roller, a yarn hooking member, a yarn removing member and a yarn removal
detecting section. The spinning device produces a spun yarn by applying
twists to a fiber bundle. The yarn accumulating roller is arranged
downstream of the spinning device in a yarn travelling direction, and
temporarily accumulates the spun yarn while rotating and winding the
spun yarn around an outer peripheral surface thereof. The yarn hooking
member is arranged downstream of the yarn accumulating roller, and
adapted to wind the spun yarn around the outer peripheral surface of
the yarn accumulating roller by integrally rotating with the yarn
accumulating roller while being in contact with the spun yarn. The yarn
removing member is capable of removing the spun yarn from the yarn
hooking member. The yarn removal detecting section detects that the
spun yarn has been removed from the yarn hooking member with the yarn
removing member.
In the spinning unit, the yarn removal detecting section can
detect whether or not a spun yarn has been removed from the yarn hooking
member. Accordingly, a failure which occurs when a yarn removal is not
detected can be prevented.
The spinning unit includes a wax applying device which is arranged
downstream of the yarn accumulating roller, and adapted to apply wax
to a travelling spun yarn. The yarn removal detecting section provided
in the wax applying device detects a travelling state of the spun yarn,
and detects removal of the spun yarn from the yarn hooking member in
accordance with the travelling state of the spun yarn. With the
detecting section provided in the wax applying device, removal of the
spun yarn from the yarn hooking member can be detected.
The yarn removal detecting section detects the spun yarn moved
in a peripheral direction of the yarn accumulating roller and on the
outer peripheral surface thereof by the yarn hooking member rotating
while making contact with the spun yarn, and detects removal of the
spun yarn from the yarn hooking member in accordance with a detection
of the spun yarn moving in the peripheral direction. With the detecting
section that detects a spun yarn moving in the peripheral direction
of the yarn accumulating roller and on the outer peripheral surface
thereof, removal of the spun yarn from the yarn hooking member can be
detected.
A spinning device is preferably an air-jet spinning device that
produces a spun yarn by twisting a fiber bundle with whirling airflow.
Also in the spinning unit including the air-jet spinning device, removal
of the spun yarn from the yarn hooking member can be detected.
A spinning machine includes a plurality of the above-described
spinning units and a service cart arranged to be capable of moving among
the plurality of spinning units. The yarn removal detecting section
is provided on the service cart, and detects the spun yarn moved in
the peripheral direction of the yarn accumulating roller by the yarn
hooking member rotating while making contact with the spun yarn. In
accordance with a detection result of the spun yarn moving in the
peripheral direction of the yarn accumulating roller, the yarn removal
detecting section detects that the spun yarn has been removed from the
yarn hooking member. By detecting the spun yarn moving in the peripheral
direction of the yarn accumulating roller using the detecting section
provided on the service cart, removal of the spun yarn from the yarn
hooking member can be detected.
The service cart is preferably at least one of a yarn joining cart
for joining spun yarns and a yarn doffing cart for moving a package
which is formed by winding the spun yarn produced by the spinning device.
By arranging the yarn removal detecting section on the yarn joining
cart or the yarn doffing cart, removal of the spun yarn from the yarn
hooking member can be detected.
A detection can be carried out as to whether or not the spun yarn
has been removed from the yarn hooking member.
According to a yarn processing method during a yarn joining
operation in a spinning machine with a spinning device, a yarn joining
device and a yarn accumulating device, directly after a yarn cut or
breakage, a low quality yarn is produced due to slip of the yarn in
the yarn accumulating device, the yarn joining operation is not started
immediately after an upper yarn from the spinning device has been guided
to the yarn joining device, but it is waited until a sufficient amount
of yarn is again collected in the yarn accumulating device to avoid
slip therein, then the first yarn of low quality is removed from the
yarn accumulating device and replaced by normal yarn produced after
a sufficient amount of yarn had again been collected in the yarn
accumulating device, and only then the yarn joining operation is started
in the yarn joining device, thus avoiding to include the low quality
yarn in the produced yarn.
According to the yarn processing method in the spinning machine
with the yarn accumulating device with a yarn accumulating roller and
a yarn hooking member, which winds the spun yarn into a package, the
low quality yarn is removed from the yarn accumulating device by
actuating a yarn removing member which removes the yarn from the yarn
hooking member and thus allows the low quality yarn to be sucked by
a suction pipe which is normally used to catch the yarn from the package.
According to the yarn processing method, the amount of potentially
low quality yarn is measured by an optical sensor at the yarn
accumulating device.
According to the yarn processing method, a further sensor is used
to check whether the yarn is indeed removed from the yarn hooking member.

WE CLAIM
1. A spinning unit comprising:
a spinning device adapted to produce a spun yarn by twisting a
fiber bundle,
a yarn accumulating roller provided downstream of the spinning
device in a yarn travelling direction and adapted to accumulate the
spun yarn by rotating and winding the spun yarn around an outer
peripheral surface thereof,
a yarn hooking member arranged downstream of the yarn accumulating
roller and adapted to wind the spun yarn around the outer peripheral
surface of the yarn accumulating roller by rotating with the yarn
accumulating roller while being in contact with the spun yarn,
a yarn removing member adapted to remove the spun yarn from the
yarn hooking member, and
a yarn removal detecting section adapted to detect a removal of
the spun yarn from the yarn hooking member.
2. The spinning unit according to Claim 1, further comprising
a wax applying device arranged downstream of the yarn accumulating
roller and adapted to apply wax to the spun yarn,
wherein the wax applying device is provided with the yarn removal
detecting section, and
the yarn removal detecting section is adapted to detect a
travelling state of the spun yarn and to detect a removal of the spun
yarn, from the yarn hooking member in accordance with the detected
travelling state of the spun yarn.
3. The spinning unit according to Claim 1 or Claim 2,wherein the
yarn removal detecting section is adapted to detect the spun yarn moved
in a peripheral direction of the yarn accumulating roller on the outer
peripheral surface of the yarn accumulating roller by the yarn hooking
member rotating while making contact with the spun yarn, and to detect
the removal of the spun yarn from the yarn hooking member in accordance
with a detection result of the spun yarn moving in the peripheral
direction of the yarn accumulating roller.
4. The spinning unit according to any one of Claim 1 through Claim
3, wherein the spinning device is an air-jet spinning device adapted
to produce the spun yarn by twisting the fiber bundle with a whirling
airflow.
5. The spinning unit according to any one of Claim 1 through Claim
4, further comprising a moving section adapted to move the yarn removing
member to a standby position where the yarn removing member is receded
from a yarn path of the spun yarn and to a yarn removal position where
the yarn removing member removes the spun yarn from the yarn hooking
member,
wherein when the yarn removal detecting section detects failure
of the removal of the spun yarn from the yarn hooking member, the moving
section moves the yarn removing member to the standby position and then
to the yarn removal position.
6. A spinning machine comprising:
a plurality of spinning units according to any one of Claim 1
through Claim 5, and
a service cart arranged capable of moving among the plurality of
the spinning units and provided with the yarn removal detecting section,
wherein the yarn removal detecting section detects the spun yarn
moved in the peripheral direction of the yarn accumulating roller by
the yarn hooking member rotating while making contact with the spun
yarn, and to detect the removal of the spun yarn from the yarn hooking
member in accordance with a detection result of the spun yarn moving
in the peripheral direction of the yarn accumulating roller.
7 . The spinning machine according to Claim 6, wherein the service
cart is at least one of a yarn joining cart adapted to join the spun
yarn and a doffing cart adapted to move a package formed by winding
the spun yarn produced by the spinning device.
8. A yarn processing method during a yarn joining operation in
a spinning machine with a spinning device, a yarn joining device and
a yarn accumulating device, wherein directly after a yarn cut or breakage,
a low quality yarn is produced due to slip of the yarn in the yarn
accumulating device, wherein the yarn joining operation is not started
immediately after an upper yarn from the spinning device has been guided
to the yarn joining device, but it is waited until a sufficient amount
of yarn is again collected in the yarn accumulating device to avoid
slip therein, then the first yarn of low quality is removed from the
yarn accumulating device and replaced by normal yarn produced after
a sufficient amount of yarn had again been collected in the yarn
accumulating device, and only then the yarn joining operation is started
in the yarn joining device, thus avoiding to include the low quality
yarn in the produced yarn.
9. The yarn processing method according to claim 8 in the spinning
machine with the yarn accumulating device with a yarn accumulating
roller and a yarn hooking member, which winds the spun yarn into a package,
wherein the low quality yarn is removed from the yarn accumulating device
by actuating a yarn removing member which removes the yarn from the
yarn hooking member and thus allows the low quality yarn to be sucked
by a suction pipe which is normally used to catch the yarn from the
package.
10 . The yarn processing method according to claim 8 or 9, wherein
the amount of potentially low quality yarn is measured by an optical
sensor at the yarn accumulating device.
11. The yarn processing method according to claims 9 and 10,
wherein a further sensor is used to check whether the yarn is indeed
removed from the yarn hooking member.
12. A spinning unit, substantially as herein described with
reference to accompanying drawings and examples.
13. A yarn processing method, substantially as herein described
with reference to accompanying drawings and examples.